1. Field of the Invention
The present invention relates to a charging/discharging control circuit and a battery apparatus which are high in safety.
2. Description of the Related Art
A battery apparatus provided with a plurality of secondary batteries connected in parallel causes the following malfunctions where one of the secondary batteries is internally short-circuited.
Since the internally short-circuited secondary battery is lowered in internal resistance and output voltage, currents flow in an opposite direction from other normal secondary batteries connected in parallel therewith. The backward currents have the possibility of becoming large currents because the internal resistance of the internally short-circuited secondary battery is low.
In order to solve the above-described problems, the related art battery apparatus is equipped with a current detection circuit provided in series with each secondary battery. For example, when the current detection circuit detects that the direction in which a current flows is opposite to the flowing direction of a current in each normal secondary battery, a discharging path to the current in the backward direction is cut off (refer to, for example, Patent Document 1).
[Patent Document 1] Japanese Patent Application Laid-Open No. 2001-185228